Jesse c



UNITED STATES PATENT OFFICE.

JESSE C. KING, OF MONTREAL, QUEBEC, CANADA.

Patented Aug. 5, 1919.

ELECTRODE.

1 312,256, Specification of Letters Patent.

No Drawing.

To all whom it may concern.

Be it known that I, Jnssn C, KING, a citizen of the United States, and resident of the city of Montreal, in the Province of Quebec and Dominion of Canada, have invented certain new and useful Improvements in Electrodes, of which the following is a full, clear, and exact description.

This invention relates to improvements in electrodes for use in electric furnaces and the like, and particularly to a covering for the electrodes designed to prevent deterioration or wasting away, not only of the electrodes, but also of the protective coatings with which the electrodes are covered.

Electric arc electrodes are subject to considerable wasting away by burning under the action of air or other oxidizing gases. If the electrode is not protected by some means, the portion exposed to the air wastes away very rapidly. Even when electrodes have been made with surface coatings, the bonding material of the coating, which is usually of a carbonaceous nature, is inclined to disintegrate.

It has been found in operating electric furnaces that electrodes, when properly protected from the oxidizing influences of the furnace gases and SUI'I'OUllCliIlg air, will last from one to six Weeks, depending upon the operating conditions of the furnace and its temperature, as well as the metals to be smelted. When a binder of a carbonaceous nature is used in an electrode coating, there is a slow disintegration or' burning away of this binder in the less intensely heated zones of the furnace, and this disintegration takes place before the coating reaches a temperature hot enough to somewhat vitrify the materials forming the coating, and,

thereby reducing if not entirely removing the further necessity for the carbonaceous binder.

To increase the life of the coating and to protect the carbonaceous or other bonding Application filed October 9, 1917. Serial No. 195,574.

materials of the electrode coatings, I have found it advantageous to paint or plaster onto the inner coating a second covering which will prevent the binder from disintegrating in the heated zone of the furnace. Such a coating is preferably made of a cement consisting of a mixture of graphite, asbestos, infusorial earth, and certain kinds of slate, bonded together with silicate of soda. This coating may be applied either before or after the electrode is baked.

If it is desired to mold the surface coating onto the carbon electrode, the latter may be used in a suitable mold as a core and the second coating may be pressed into the mold around the core in the usual manner. If the second coating is to be pasted onto the core, a trowel or other suitable implement may be used and this second coating in plastic condition may be pasted onto the roughened surface of the core, in as even a manner as possible. To spray the coating onto the core any suitable implement, such as a cement gun, may be employed.

Having thus described my invention, what I claim is:

1. An electrode for an electric furnace comprising a core, a coating of non-oXidiz ing material applied to the core, and a second coating of protective material applied to the inner coating.

2. An electrode for an electric furnace JESSE C. KING.

Copies of this patent may be obtained for five cents each, by addressing the commissioner of ratents,

' Washington, D. G. 

